// This code is derived from jcifs smb client library <jcifs at samba dot org>
// Ported by J. Arturo <webmaster at komodosoft dot net>
//  
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
using System;
using SharpCifs.Util;
using SharpCifs.Util.Sharpen;

namespace SharpCifs.Smb
{
    internal class SmbComNegotiateResponse : ServerMessageBlock
    {
        internal int DialectIndex;

        internal SmbTransport.ServerData Server;

        internal SmbComNegotiateResponse(SmbTransport.ServerData server)
        {
            this.Server = server;
        }

        internal override int WriteParameterWordsWireFormat(byte[] dst, int dstIndex)
        {
            return 0;
        }

        internal override int WriteBytesWireFormat(byte[] dst, int dstIndex)
        {
            return 0;
        }

        internal override int ReadParameterWordsWireFormat(byte[] buffer, int bufferIndex)
        {
            int start = bufferIndex;
            DialectIndex = ReadInt2(buffer, bufferIndex);
            bufferIndex += 2;
            if (DialectIndex > 10)
            {
                return bufferIndex - start;
            }
            Server.SecurityMode = buffer[bufferIndex++] & unchecked(0xFF);
            Server.Security = Server.SecurityMode & unchecked(0x01);
            Server.EncryptedPasswords
                = (Server.SecurityMode & unchecked(0x02)) == unchecked(0x02);
            Server.SignaturesEnabled
                = (Server.SecurityMode & unchecked(0x04)) == unchecked(0x04);
            Server.SignaturesRequired
                = (Server.SecurityMode & unchecked(0x08)) == unchecked(0x08);
            Server.MaxMpxCount = ReadInt2(buffer, bufferIndex);
            bufferIndex += 2;
            Server.MaxNumberVcs = ReadInt2(buffer, bufferIndex);
            bufferIndex += 2;
            Server.MaxBufferSize = ReadInt4(buffer, bufferIndex);
            bufferIndex += 4;
            Server.MaxRawSize = ReadInt4(buffer, bufferIndex);
            bufferIndex += 4;
            Server.SessionKey = ReadInt4(buffer, bufferIndex);
            bufferIndex += 4;
            Server.Capabilities = ReadInt4(buffer, bufferIndex);
            bufferIndex += 4;
            Server.ServerTime = ReadTime(buffer, bufferIndex);
            bufferIndex += 8;
            Server.ServerTimeZone = ReadInt2(buffer, bufferIndex);
            bufferIndex += 2;
            Server.EncryptionKeyLength = buffer[bufferIndex++] & unchecked(0xFF);
            return bufferIndex - start;
        }

        internal override int ReadBytesWireFormat(byte[] buffer, int bufferIndex)
        {
            int start = bufferIndex;
            if ((Server.Capabilities & SmbConstants.CapExtendedSecurity) == 0)
            {
                Server.EncryptionKey = new byte[Server.EncryptionKeyLength];
                Array.Copy(buffer,
                           bufferIndex,
                           Server.EncryptionKey,
                           0,
                           Server.EncryptionKeyLength);
                bufferIndex += Server.EncryptionKeyLength;
                if (ByteCount > Server.EncryptionKeyLength)
                {
                    int len = 0;
                    // TODO: we can use new string routine here
                    try
                    {
                        if ((Flags2 & SmbConstants.Flags2Unicode) == SmbConstants.Flags2Unicode)
                        {
                            while (buffer[bufferIndex + len] != unchecked(unchecked(0x00))
                                   || buffer[bufferIndex + len + 1] != unchecked(unchecked(0x00)))
                            {
                                len += 2;
                                if (len > 256)
                                {
                                    throw new RuntimeException("zero termination not found");
                                }
                            }
                            Server.OemDomainName = Runtime.GetStringForBytes(buffer,
                                                                             bufferIndex,
                                                                             len,
                                                                             SmbConstants.UniEncoding);
                        }
                        else
                        {
                            while (buffer[bufferIndex + len] != unchecked(unchecked(0x00)))
                            {
                                len++;
                                if (len > 256)
                                {
                                    throw new RuntimeException("zero termination not found");
                                }
                            }
                            Server.OemDomainName = Runtime.GetStringForBytes(buffer,
                                                                             bufferIndex,
                                                                             len,
                                                                             SmbConstants.OemEncoding);
                        }
                    }
                    catch (UnsupportedEncodingException uee)
                    {
                        if (Log.Level > 1)
                        {
                            Runtime.PrintStackTrace(uee, Log);
                        }
                    }
                    bufferIndex += len;
                }
                else
                {
                    Server.OemDomainName = "";
                }
            }
            else
            {
                Server.Guid = new byte[16];
                Array.Copy(buffer, bufferIndex, Server.Guid, 0, 16);
                Server.OemDomainName = "";
            }
            // ignore SPNEGO token for now ...
            return bufferIndex - start;
        }

        public override string ToString()
        {
            return "SmbComNegotiateResponse["
                        + base.ToString()
                        + ",wordCount=" + WordCount
                        + ",dialectIndex=" + DialectIndex
                        + ",securityMode=0x" + Hexdump.ToHexString(Server.SecurityMode, 1)
                        + ",security=" + (Server.Security == SmbConstants.SecurityShare
                                            ? "share"
                                            : "user")
                        + ",encryptedPasswords=" + Server.EncryptedPasswords
                        + ",maxMpxCount=" + Server.MaxMpxCount
                        + ",maxNumberVcs=" + Server.MaxNumberVcs
                        + ",maxBufferSize=" + Server.MaxBufferSize
                        + ",maxRawSize=" + Server.MaxRawSize
                        + ",sessionKey=0x" + Hexdump.ToHexString(Server.SessionKey, 8)
                        + ",capabilities=0x" + Hexdump.ToHexString(Server.Capabilities, 8)
                        + ",serverTime=" + Extensions.CreateDate(Server.ServerTime)
                        + ",serverTimeZone=" + Server.ServerTimeZone
                        + ",encryptionKeyLength=" + Server.EncryptionKeyLength
                        + ",byteCount=" + ByteCount
                        + ",oemDomainName=" + Server.OemDomainName + "]";
        }
    }
}
